Sliding doors typically have been designed for installation in areas where hinged swinging doors may not practically operate or where large rolling panes of glass are aesthetically desirable. Sliding doors have become increasingly popular for partitioning adjacent rooms or for serving as exterior doors to the outdoors.
Access to areas partitioned by doors has historically been controlled by latches or locks, and alternatively, by judgment and common-sense. When a partitioned area contains a hazard or danger, a latch or lock may secure the door against intrusion. For example, a latch may be used to prevent a child's access to a pool area. For convenience, latches and locks have been traditionally located midway between the top and bottom of a standard door. Such a placement of a latch accommodates individual users having varying heights. However, such low placement of latches enables smaller children to also activate the latch and pass through the door. Furthermore, some doors, and in particular sliding and bar doors, are not necessarily latched when in a closed but unlocked positions and may be opened or retracted merely by applying pressure to any surface of the door and pushing or sliding. Thus, their effectiveness is preventing children from passing through the door may be limited.
Because of the unappreciated and unknown dangers beyond a door that await small children, devices for limiting access by children have been developed and are known in the art. Commonly known devices such as striker hooks for cabinet doors, free-spinning door knob covers, and security chains mounted out of reach have been developed for use in child-proofing hinged swinging doors. However, child-proof access limiting devices for sliding doors are virtually unknown and non-existent. Furthermore, many child-proof access limiting devices may become a nuisance for adults to operate because of the additional access limitations they overlay on adult users. When such devices become obstructive to adults, such devices are frequently disengaged or bypassed thus minimizing their beneficial use. For example, a security chain when placed on the interior of a sliding door and engaged, may limit the travel of the sliding door when a child attempts to open it. Even as the slack in the chain is taken up by the opening of the sliding door, the door remains child-proof as the opening is insufficient for a child to pass through. However, the engaged safety chain on the interior of the sliding door prohibits an adult user of the sliding door from entering from the exterior side. Other access limiting devices, such as stops that restrict door travel, that are only overrideable from one side of the door equally become a nuisance to adult users. Furthermore, these types of safety chains must be positively locked to function and this provide limited protection compared to systems that lock automatically when the door closes.